The ARU has hailed the ''concussion bin'' trial a success in Australia but conceded it is too early to know whether the measures will be enough to prevent long-term brain damage to players.

Wallabies doctor Warren McDonald said the eight-month-old trial of a five-minute concussion substitution rule, sometimes nicknamed the ''head bin'', was a crucial step towards making the game safer and had worked well in practice during Test and Super Rugby matches.

But with little clear information available that causally links repeated concussions with long-term brain injuries, McDonald said the sport was locked in a waiting game.

''I think we don't know how much to be concerned [about concussion] and I think that will become clear in the coming years,'' he said.

Advertisement

''But I think the important message is we have recognised that there is the potential for there to be problems, and that if we treat concussion appropriately then it should reduce the risk of any long-term problems developing in people.''

The effects of concussion in contact sports have come under increased scrutiny after the deaths of several NFL and ice hockey players who claimed to be suffering from brain injuries as a result of their time playing.

In the US, about 4000 former NFL players are suing the league over alleged negligence on its behalf. In Australia, the plights of AFL great Greg Williams and NRL player Shaun Valentine as well as Wallabies legend Elton Flatley, who retired at 28 due to repeated serious concussions, have attracted attention.

While the most recent consensus statement from international experts on concussion in sport - a number of whom are Australian - found ''the speculation that repeated concussion or subconcussive impacts cause [the degenerative disease chronic traumatic encephalopathy] remains unproven'', the professional football codes in Australia recognised more needed to be done to protect athletes.

Rugby was the first contact sport here to tighten its safeguards. Last August the ARU, in line with IRB guidelines, began a trial of the concussion bin, which gives teams a five-minute temporary substitution window to assess off the field a player they suspect is concussed.

From a medical perspective it is a vast improvement on the previous rules, under which medicos had an average of 82 seconds to make a call about a player, on the field of play, while play continued.

Wallabies lock Sitaleki Timani was the first player taken to the concussion bin after colliding with teammate Anthony Faingaa during the first Bledisloe Cup match in Sydney last August.

Timani was assessed, cleared to return to the field and was given the all-clear in a mandatory post-match assessment and check-ups in the days following.

More recently, NSW hooker John Ulugia was pulled from the field after a head knock during the Waratahs' home game against the Force last Sunday and was also cleared to play on.

Though only eight months old, McDonald said the trial was producing some consistent results. The majority of players kept off the field after being sent to the bin were diagnosed with concussion after the game or during subsequent check-ups, while the majority of those allowed to rejoin play were given the all-clear in subsequent assessments.

This year the AFL introduced a rule allowing a substitute player wearing a green vest to replace a potentially concussed player for up to 20 minutes.

McDonald said all sports recognised concussion had to be treated seriously despite the controversy over its effect in the long term.

''I think that's a great message that we're sending, that we need to treat this appropriately across all levels of the game,'' McDonald said. ''Is it enough? We won't know for some period of time. But it is certainly some big steps forward without, in my mind, changing the fabric of the game.''

3 Apr
Pat McCabe's frustrating injury curse is over and ACT Brumbies coach Jake White is prepared to rush the star centre straight into the starting team to play the Southern Kings at Canberra Stadium on Friday night.